This application is for renewal funding of research training in liver biology and disease at UCSF. The rationale is two-fold: (1) the field is growing rapidly and currently has insufficient numbers of well-trained investigators, and (2) the resources and environment at UCSF for training in liver research are exceptional. The program, which is based in the Division of Gastroenterology, provides two years of support to trainees who seek an intensive grounding towards a career as academic hepatologists. It is inter-disciplinary, encompassing the Department of Epidemiology and Biostatistics and the Liver Transplant Program for those undertaking clinical and outcomes research, and the UCSF Liver Center for those engaged in laboratory-based research. The mentor group comprises 13 faculty from the Departments of Medicine, Pathology, Biochemistry and Microbiology/Immunology. All have research programs in liver research, experience in training, and a record of working together. The program is overseen by a Steering Committee, which is responsible for screening applicants, tendering offers, and monitoring progress. Applications for admission will be solicited annually by national advertisement. The largest candidate pool will be M.D. applicants to the Investigator (research-intensive) track of the UCSF subspecialty program in Gastroenterology, but the process will be open to others including Ph.D.'s. The successful applicant will have a record of accomplishment in the form of publications and, in many cases, both M.D. and Ph.D. degrees. Applicants with a Ph.D. degree only must have a strong liver focus and orientation to translational research. The range of training within the program is broad, from clinical epidemiology, genetics, health outcomes and policy, to cell biology, organogenesis, immunology, host-pathogen interactions and fibrosis/carcinogenesis. Coincident with their research, trainees are provided formal instruction in basic and clinical sciences as part of the UCSF graduate programs in Clinical Research, Biomedical Sciences and Biological Sciences. A core curriculum encompassing ethical conduct of research and effective scientific communication is required of all students. Graduates of this research training in hepatology will be ready to assume a faculty-level position and to compete for individual extramural funding.